霧滴抑制劑控制電鍍槽鉻酸霧滴之研究

A Study of Chromium Mist Control with Mist Suppressant in Chromium Electroplating Tanks

抑制劑是電鍍業常用的控制方法之一，本研究以實際鉻電鍍生產工廠為對象，以光散射直讀式儀器測量粒徑濃度與時間變化，探討抑制劑影響趨勢，並以階梯衝擊器進行工廠定點作業環境測試，評估電鍍業鉻酸霧滴的粒徑及工廠使用抑制劑的效果。研究結果顯示電鍍過程中若無適當工程控制鍍鉻槽會產生大量的鉻酸霧滴，霧滴質量中位粒徑約為21.3μm﹐而粒徑大於15μm 的微粒質量比率高達80%﹐而添加抑制劑後粒徑也類似。使用抑制劑來控制電鍍過程中所產生之鉻酸霧滴濃度，研究工廠實際使用經驗效果雖高達79.5%，但霧滴濃度仍大於100μg/m3，因此建議使用抑制劑來控制電鍍過程中所產生之鉻酸霧滴仍應搭配其他工程控制方法進行控制，並應注意管理制度的建立。

Application of mist suppressant is one of the common practices to control chromium mist in chrome electroplat ing plants. The effect of mist suppressant was evaluated through area sampling at an electroplating factory. The particle size distribution of the mist was measured by a cascade impactor and the number concentration was measured by a real-time light scattering monitor. Effectiveness of mist suppressant was then determined by the particle size distribution of mist. Results revealed that in the factory which had no proper engineering control systems vast quantity of chromic acid mist was found. The mass medium aerodynamic diameter of chromium mist was 21.3μm and the droplets with aerodynamic diameter greater than 15μm accounted for 80%. Even the efficiency of mist suppressant alone was 79.5%, the concentration of chromium mist in the study was greater than 100μg/m3. Therefore, mist suppressant alone cannot provide sufficient protection for workers. It must be applied in conjunction with other engineering control techniques.